Association of lymphoid leukosis virus and performance in a randombred layer population.

The association of subclinical infections with lymphoid leukosis virus and performance was investigated in a randombred White Leghorn type population. The proportion of birds shedding group specific (gs) antigen into their egg albumen was high (23.8%). Birds with gs antigen in their albumen matured later, produced fewer and smaller eggs, and grew less rapidly tha their nonshedding counterparts.